1. Field of the Invention
This invention generally relates to a multiple sprocket chainwheel for bicycle derailleurs with at least two sprockets which have different numbers of teeth, and which are non-rotationally located on a chainwheel bushing, whereby between the sprockets there are spacer connecting rings, with bearings and a drive bushing which is driven in the driving direction of rotation by the chainwheel bushing by means of a freewheel mechanism.
2. Background Information
A multiple sprocket chainwheel is disclosed, for example, in German Patent Application No. 28 42 362, which essentially relates to the axial mounting of a complete driving part consisting of a multiple sprocket chainwheel, bearing and freewheel mechanism. The multiple sprocket chainwheel, as shown in particular in FIG. 3 in German Patent Application No. 28 42 362, is comprised of a pre-assembled unit which is held together by one or more screws which run axially and which clamp the numerous sprockets together with connecting rings. Such a package of sprockets is slid onto a chainwheel bushing and is axially fixed in the stop position, or contact position. After the fixing of the multiple sprocket chain wheel on the chainwheel bushing, the axial bracing of the sprockets and connecting rings is essentially irrelevant to the function of the chain drive. The only advantage, essentially, is the ease of handling the multiple sprocket chainwheel before and after its installation on the bicycle in its axially fixed position on the chainwheel bushing.
The initial installation and reinstallation of a multiple sprocket chainwheel as disclosed in German Patent Application No. 28 42 362 can essentially only be done using tools, which is a particular disadvantage in competitive racing, if the composition of a multiple sprocket chainwheel has to be changed quickly with regard to the number of teeth of its individual sprockets.
On the other hand, a multiple sprocket chainwheel, in accordance with at least one embodiment of the present invention, with the use of essentially a single type of connecting ring, can be assembled as desired without tools, whereby it is possible for the initial installer to prepare preassembled multiple sprocket chainwheels and to supply the retail store with the individual sprockets and the connecting rings.
Thus it becomes easy to replace individual sprockets, whereby such an installation can be done by practically anyone. The position of the sprockets with respect to one another with regard to their mutual orientation, their tooth configuration and shape can easily be achieved by means of specially located clamping devices, which are preferably located in a defined position in relation to an asymmetrically located longitudinal groove and profile, which profile is preferably used to slide the sprockets and the connecting rings onto the chainwheel bushing.